According to a Sigma press release, the new USB dock will hit digital shelves in early May for a street price of $60 and an MSRP of $80. The dock has people excited as it seems to be the first product of its kind, and Sigma lens users have been itching to get their hands on it ever since news broke of its existence.

Looks like Sigma is brilliant here. Allowing the zoom lenses to have focus adjustments for 4 focal lengths. For example, the 17-70 will allow focus adjustments at 17mm, 28mm, 50mm, and 70mm. No more Tamron 17-50 focus adjustment issues.

Sigma service (here in Canada) calibrated my 50-500 OS to my K-5 because I found it would back-focus at 50mm and slightly front-focus at 500mm. They fixed it for all focal lengths as part of a free service! When I asked if they used a variant of this upcoming USB tool, they said "yes, but much less user-friendly." Essentially, they use a cannibalized K-mount as the interface to reprogram the older lens ROM, and the data comes from an Excel spreadsheet where they've plugged in the test results from various focal-lengths. This looks like a much better method! (Naturally, Canon-mount is first, with Nikon next... no idea if or when Sony or Pentax will join the fray!)

It would be weird if there isn't compatibility with Pentax mount, as the new Sigma 35 F1.4 has a USB dock and is coming out for Pentax.

Yes, but this is Sigma, who sometimes remove the OS (or HSM long ago) from a lens for Pentax or Sony and charge the same amount! From what I've seen, the initial design for this system was a USB port in the side of the lens, but now it is a "dock" which is basically a USB lens mount with contacts for the Sigma data port. So, while it would be weird for Sigma not to make a Pentax version given that some compatible lenses will be PK, it is not unimaginable...